The present invention relates to a device for measuring and controlling the pH of the atmosphere in a high pressure steamer to be applied for wet heat treating a textile product such as a cloth at an elevated pressure.
A high pressure steamer has been applied for pretreating or dyeing a long cloth produced commercially with high speed continuously. A high pressure steamer for such a use is provided with a seal mechanism, which is to allow the continuous pass of a cloth to be treated therethrough while maintaining the high pressure wet heat in the steamer body, respectively to the cloth inlet and the cloth outlet of the steamer body. Treatment of a long cloth, for instance scouring, bleaching and dyeing, can be done speedily and continuously by wet heat treating the cloth at a temperature, for instance, about 160.degree. C. under pressure while transporting the cloth continuously through the steamer body.
However, in subjecting a cloth to such treatment as dyeing by using such a high pressure steamer, the atmosphere in the interior of the steamer body becomes frequently acidic due to the evaporation of acidic components contained in the dye solution, so that a uniform continuous dyeing of a cloth becomes impossible due to the fluctuation of pH in the atmosphere and there occur further such problems that the inner walls of the steamer body are corroded, but it has been impossible conventionally to measure and control the pH of the atmosphere in the interior of the steamer body during operation.